Help with bypassing a JBL stock amp in a 2004 Toyota Tundra Limited

I recently purchased a Tundra and so far I love it! I also recently purchased a new Kenwood deck, MA Audio's MA800XL Pair 800 Watt 8 Inch Subsand, and a MA Audio M700xe AMPLIFIER.

I pulled out my factory HU, bought the harness and was ready for install. I realized that the stereo is a JBL with a preamp behind the driver side rear wall. I have to order a new custom harness that can bypass the stock amp. I would rather take out the amp and do a install like the mods show here by Steve Brown,

http://www.caraudiomag.com/technical/0702_cae_alpine_amplifier_installation/index.html  

I am going to put my 2 8" subs in the storage under the seat and maybe a 10" JL Audio sub in the compartment under the rear passenger side seat.(maybe).

Anyway does anyone know of a easy way to take out the factory amp and install my own without having to rewire my whole system? Any help or links to articles would be great.    

ARE YOU REPLACEING THE FACTORY SPEAKERS IN THE DOORS, IF NOT I HIGHLY RECCOMEND THAT YOU KEEP THE FACTORY AMP WORKING BUY USING THE METRA TYOT-01 AND THEN JUST ADD A BASS AMP AND SUBS, USE THE CROSSOVER IN THE HEAD UNIT TO KEEP THE FACTORY SPEAKERS FROM GETTING BASS . JEFF MEECE MECP TOP 100  

Hi Jeff
you mentioned the METRA TYOT-01 (TYTO01) which claims "This digital interface provides full integration of aftermarket car entertainment and navigation systems with factory equipment" and seems to be for all new toyota models.
My questions:
1. will this work for the Avalon 2005 with the non SatNav JBL stereo with cassette?
2. will it keep the steering wheel controls operating, not just the JBL unit but operate the replacement unit's skip-FFW etc..? if not, how to control the new unit?
3. I read on this website that the mag has a "2007 Avalon project" where the standadrd unti is replaced by an Alpine DVD unit.. where can I find out more about the whole project.?
cheers for any help you can give me
doobre  

Yes It should work with your car, double check with metra . The steering wheel controls will need another interface. Check out the PAC SWI-JACK. Depending on how many buttons you have on the steering wheel you have will determine what you can do with the PAC S/W controller . If you never used one you can programme any button to do any thing with the head unit. Jeff Meece MECP top 100  

I have a 2004 Toyota Tundra double cab.  I checked the Metra specs and it says it only works for the '05 and up Tundras.  Is there anything I can use to bypass my amp to add an aftermarket amp and subs without changing the factory stereo?  I say JL audio's product for this, but it was ~$300, I'm not trying to pay that much.  Let me know if any of ya'll know about a product that will help.  Thanks.  

shane from Cambridge,mn writes,i own a 94' Cadillac seville sls, with the factory stereo,and i have a BOSE factory amp in my trunk-i wired up a outline converter to my 6x9 wires in the trunk to by-pass the amp
(other wise i'd have to re-wire all my factory speakers),but now im getting feed back when i turn my stereo off-i have the remote wire comming off the stereo-i had it off my power antenna first then i switched it to the stereo.I have 2 15 inch kicker CVX's,powered by 400x2  and 2 12 inch kicker CVR's,powered by 150x2-after i turn my car off-it wont start again for an hour or two-I get full power-but it wont turn over-then an hour later-it will fire right back up-i just replaced the starter-THATS NOT IT!!-i dont know what to do?---why do i get feedback humm and why wont my car start again right away-no clicks or anything...shane